The invention claimed is:1. A method, performed in a network node within a telecommunications network, for End-to-End, E2E, User Equipment, UE, trajectory network automation, the method comprising:receiving, from a requesting entity, information identifying a future E2E UE trajectory, the identified future E2E UE trajectory comprising a start location, an end location, and zero or more intermediate locations between the start location and the end location;calculating an E2E mobility trajectory prediction for the identified future E2E UE trajectory and for at least one alternative E2E UE trajectory, wherein the E2E mobility trajectory prediction comprises a predicted UE experience for the identified future E2E UE trajectory and another predicted UE experience for the at least one alternative E2E UE trajectory, each predicted UE experience including a cost for a corresponding E2E UE trajectory; andsending, to the requesting entity, the calculated E2E mobility trajectory predictions for the identified future E2E UE trajectory and the at least one alternative E2E UE trajectory, from which the requesting entity will select an E2E UE trajectory.2. The method of claim 1 wherein the network node comprises at least one of:a Network Data Analytics Function, NWDAF; anda Policy Control Function, PCF.3. The method of claim 1 wherein the requesting entity comprises an untrusted application function.4. The method of claim 3 wherein the request from the requesting entity is received from a Network Exposure Function, NEF, or a Service Capability Exposure Function, SCEF.5. The method of claim 1 wherein the requesting entity comprises an application hosted by a UE.6. The method of claim 5 wherein the request from the requesting entity is received from a User Plane Function, UPF.7. The method of claim 1 wherein receiving the information identifying a future E2E UE trajectory comprises receiving information comprising network slice characteristics.8. The method of claim 7 wherein the network slice characteristics comprise:an expected average downlink throughput per step or turn;an expected average downlink throughput during the stops;an expected average uplink throughput per step or turn;an expected average uplink throughput during the stops;an expected average latency per step or turn;an expected average latency during the stops;an expected average jitter per step or turn;an expected average jitter during the stops;an expected average reliability;an expected cost of tolls; and/oran expected cost per bit.9. The method of claim 1 wherein receiving a start location comprises receiving:an estimated time to start;a latitude or equivalent;a longitude or equivalent; and/oran altitude or equivalent.10. The method of claim 1 wherein receiving an end location comprises receiving:a latitude or equivalent;a longitude or equivalent; and/oran altitude or equivalent.11. The method of claim 1 wherein receiving zero or more intermediate locations comprises receiving one or more stops or proposed turns.12. The method of claim 11 wherein receiving a stop comprises receiving:an estimated stop time;a latitude or equivalent;a longitude or equivalent; and/oran altitude or equivalent.13. The method of claim 11 wherein receiving a proposed turn comprises receiving:a new heading or change of direction;a latitude or equivalent;a longitude or equivalent; and/oran altitude or equivalent.14. The method of claim 13 wherein a new heading or change of direction comprises an indication of right, left, up, down, or back.15. The method of claim 1 wherein the predicted UE experience for the identified future E2E UE trajectory comprises:an identifier of the proposed route;an estimated time of arrival of the proposed route;an expected average downlink throughput per step or turn;an expected average downlink throughput during the stops;an expected average uplink throughput per step or turn;an expected average uplink throughput during the stops;an expected average latency per step or turn;an expected average latency during the stops;an expected average jitter per step or turn;an expected average jitter during the stops;an expected average reliability;an expected cost of tolls; and/oran expected cost per bit.16. The method of claim 1 wherein the predicted UE experience for the at least one alternative E2E UE trajectory comprises:an identifier of the proposed route;an estimated time of arrival of the proposed route;an expected average downlink throughput per step or turn;an expected average downlink throughput during the stops;an expected average uplink throughput per step or turn;an expected average uplink throughput during the stops;an expected average latency per step or turn;an expected average latency during the stops;an expected average jitter per step or turn;an expected average jitter during the stops;an expected average reliability;an expected cost of tolls; and/oran expected cost per bit.17. The method of claim 1, further comprising:receiving, from the requesting entity, information identifying a selected E2E UE trajectory; andadjusting the telecommunications network based on the selected E2E UE trajectory, wherein adjusting the telecommunications network comprises at least one of:sending mobility management and optimization information to a Radio Access Network, RAN; andadjusting the telecommunications network to deliver the predicted UE experience of the selected E2E UE trajectory.18. The method of claim 17 wherein receiving the information identifying the selected E2E UE trajectory comprises receiving information identifying a selected route.19. The method of claim 17 wherein sending the mobility management and optimization information to the RAN comprises sending the mobility management and optimization information to a Next Generation, NG, RAN.20. The method of claim 17 wherein sending the mobility management and optimization information to the RAN comprises sending the mobility management and optimization information directly to the RAN.21. The method of claim 17 wherein sending the mobility management and optimization information to the RAN comprises sending the mobility management and optimization information via one or more of:a Core Access and Mobility Management Function, AMF;an Operation and Maintenance, O&M, function; anda Network Slice Selection Function, NSSF.22. The method of claim 1 wherein each E2E mobility trajectory prediction is calculated based on at least one of a current network configuration and a predicted network configuration.23. A network node for End-to-End, E2E, User Equipment, UE, trajectory network automation, the network node comprising:one or more processors; andmemory storing instructions executable by the one or more processors, whereby the network node is operable to:receive, from a requesting entity, information identifying a future E2E UE trajectory, the E2E UE trajectory comprising a start location, an end location, and zero or more intermediate locations between the start location and the end location;calculate an E2E mobility trajectory prediction for the identified future E2E UE trajectory and for at least one alternative E2E UE trajectory, wherein the E2E mobility trajectory prediction comprises a predicted UE experience for the identified future E2E UE trajectory and another predicted UE experience for the at least one alternative E2E UE trajectory, each predicted UE experience[M] including a cost for a corresponding E2E UE trajectory; andsend, to the requesting entity, the calculated E2E mobility trajectory predictions for the identified future E2E UE trajectory and the at least one alternative E2E UE trajectory, from which the requesting entity will select an E2E UE trajectory.24. The network node of claim 23, further operable to:receive, from the requesting entity, information identifying a selected E2E UE trajectory; andadjust the telecommunications network based on the selected E2E UE trajectory, wherein adjusting the telecommunications network comprises at least one of:sending mobility management and optimization information to a Radio Access Network, RAN; andadjusting the telecommunications network to deliver the predicted UE experience of the selected E2E UE trajectory.25. The method of claim 23 wherein each E2E mobility trajectory prediction is calculated based on at least one of a current network configuration and a predicted network configuration.26. A non-transitory computer readable medium storing software instructions that, when executed by one or more processors of a network node for End-to-End, E2E, User Equipment, UE, trajectory network automation, cause the network node to:receive, from a requesting entity, information identifying a future E2E UE trajectory, the E2E UE trajectory comprising a start location, an end location, and zero or more intermediate locations between the start location and the end location;calculate an E2E mobility trajectory prediction for the identified future E2E UE trajectory and for at least one alternative E2E UE trajectory, wherein the E2E mobility trajectory prediction comprises a predicted UE experience for the identified future E2E UE trajectory and another predicted UE experience for the at least one alternative E2E UE trajectory, each predicted UE experience including a cost for a corresponding E2E UE trajectory; andsend, to the requesting entity, the calculated E2E mobility trajectory predictions for the identified future E2E UE trajectory and the at least one alternative E2E UE trajectory, from which the requesting entity will select an E2E UE trajectory;receive, from the requesting entity, information identifying a selected E2E UE trajectory; andadjust the telecommunications network based on the selected E2E UE trajectory, wherein adjusting the telecommunications network comprises at least one of:sending mobility management and optimization information to a Radio Access Network, RAN; andadjusting the telecommunications network to deliver the predicted UE experience of the selected E2E UE trajectory.